The author of the thesis explains that the creation of biofilms is a transformation process that initially involves knowledge of the physical-chemical characteristics of their raw materials, such as starches, proteins, lipids and additives to the process with plasticizing agents. Starch is the most studied in the literature, due to its abundance in the plant kingdom and its high degradability.
“Quinoa grain is a very rich source of starch – a macromolecule that allows the formation of films – and proteins and lipids. There is a lot of research on their nutritional properties, such as flour and amino acids, but this is the first exploratory study related to biomaterials”, he informs.
Patrícia Araujo Farro chose Real quinoa for its higher starch content, 73%, compared to 12,8% protein and 6,3% lipids. From this grain, she extracted three raw materials: wholemeal flour, obtained by dry grinding the grain; flour by wet extraction, partially defatted and deproteinized; and starch, processed in a way that does little damage to the granule.
“From whole quinoa flour, we obtained a film with a bright yellowish color, optical properties that were attenuated in the flour by wet extraction. The starch resulted in a film with transparency comparable to that of polypropylene”, explains the researcher.
According to her, the biofilms presented good characteristics in terms of barrier (permeability to water vapor and gases), mechanics (in tensile and perforation tests) and solubility. “We have shown that quinoa grain derivatives can actually form biofilms that deserve to be tested for use in sectors such as food, agriculture and pharmaceuticals.”
The most common application of films is in food coverage and packaging, and may contain antioxidants, antimicrobials or additives that aim to slow down the rate of product deterioration. “The biofilms we created may even be edible, but this would require other preparation conditions that we did not test”, says the study author.
Requirements – Patrícia Araujo Farro states that research into the production of biodegradable films responds to three current demands in the world, starting with the replacement of plastics, for environmental reasons. “The second is to use regional resources. We have many studies on corn and wheat, but we have different varieties of forgotten grains in South America, which allow us to obtain new raw materials.”
The third premise, as the researcher adds, is biodegradability. “By obtaining raw materials derived from natural resources, with the least amount of chemical processing, we will be sure that the biodegradability of this material will be one hundred percent. There are a series of methodologies that have not yet been explored, such as chemical and biochemical modifications, capable of improving results with quinoa.”
Professor Florência Menegalli, who supervised the doctoral thesis, informs that her group of researchers at FEA has been working with proteins for a long time, always in the development of biomaterials. “These products still have problems that we are trying to solve, until they can replace synthetic plastics. We have a lot of work ahead of us.”
The teacher explains that there are mixtures of natural and synthetic materials that are also biodegradable. “It turns out that we will always be tied to oil. What we are looking for are materials that are absolutely hydrophilic, but also natural, meeting today's double demands. We investigated other grain derivatives with this objective, which offer more soluble but less resistant biofilms – this is an aspect we seek to improve.”
Partners – Florência Menegalli emphasizes that research with biomaterials is always carried out together with Professor Paulo Sobral, from USP, and thanks to various funding, such as from Fapesp, Capes, CNPq, Cyted and some bilateral agreements with Spain, Portugal and countries in America Latin.
Patrícia Araujo Farro, by the way, had the support of several institutions to make her research viable. He created the biofilms and carried out part of the characterization analyzes of these materials at the Food Technology Laboratory (LTA) at USP, at the X-ray Diffraction Laboratory of Professor Lizandro Pavie (with the collaboration of specialist Alfredo Fraymann) and in other laboratory units from Unicamp.
The rheological analyzes of starch were made possible thanks to the invitation of Professor Arturo Bello Perez for an internship at the Center for Biotic Products (Ceprobi), at the Instituto de Politécnico Nacional de México, in Yautepec. The samples brought by the author of the thesis (Real, Amarillo de Maranganí, Killawaman, the improved 5460, Blanca de Junín and Mantaro) were donated by the Instituto Nacional de Investigación y Extensión Agraria (Inia), in Cajamarca, Peru.
Quinoa grain becomes a delicacy abroad
The quinoa grain became better known in Brazil only recently, due to the praise of its nutritional properties by the media dedicated to topics about quality of life. For now, however, quinoa is still served as a delicacy in very few restaurants and with prices to match – in Campinas, a box with 200 grams of grains sells for almost R$20.
“I have heard many statements that quinoa grain and amaranth, another pseudocereal, are widely consumed in my country, which is a lie. If it were true, we would have the least malnourished population in the world, as the nutritional quality of the grain is quite high”, says Patrícia Araujo Farro, who is Peruvian.
According to the researcher, in terms of proteins, quinoa contains all the essential amino acids for human consumption and has an external surface resin called saponin, which has antifungal and hypocholesterimizing properties.
“Quinoa grain is consumed by a very restricted Andean population of peasants, and is even known pejoratively as 'Indian food'. Spanish literature, at the time of discovery, refers to 'Indian rice' or 'rice of the Americas'. Over time, the grain was largely forgotten by the majority of the population”, explains Patrícia Araujo Farro.
In fact, when cooked, the quinoa grain opens up like rice, up to twice its diameter. But Andeans also mix quinoa with llama or alpaca meat, also using it for soups and sweets.
The researcher finds it important to highlight that the quinoa grain is difficult to adapt to other soils outside the Andean cradle – formed by Bolivia, Peru, the north of Argentina and Chile, and the mountains of Ecuador and Colombia. “At least in Peru, the grain can be grown from sea level to 5 meters above, being resistant to arid soils and rarefied air. In fact, the best quality of the grain is obtained at high altitudes.”
It celebrates the interest in quinoa abroad, mainly in Europe and North America, which buy the semi-processed grain to consume it in the form of cereal bars or flakes. “I feel a lot of joy at the spread of the grain abroad, but also sadness because within Peru there is no support to diversify its processing, consumption and above all its culture”.
Patrícia Araujo Farro highlights the important growth in cultivation from the 1970s onwards, due to exports, but assures that the scale could be much larger. “In this sense, what I seek with this work, personally, is to promote the application of quinoa grain in other products that may also be of interest to industries, starting with biomaterials”.
EAn unprecedented study developed at Unicamp resulted in the obtaining of biodegradable films from derivatives of the quinoa grain, a pseudocereal originating from Andean South America. The biofilms obtained by the casting method showed good mechanical properties and solubility resistance. It was an exploratory experience, but it opens up the prospect of using these quinoa derivatives in biomaterials in the future, replacing conventional plastic films, which protect food but pollute the environment. 
PRESS ROOM - � 1994-2008 State University of Campinas / Press Office